In general daily life, you can see all kinds of lighting equipment everywhere, for examples, fluorescent lamps, street lamps, table lamps, art lamps and so on. In the above lighting equipment, the incandescent light bulb has traditionally been used as a light source. In recent years, light-emitting diode (LED) has been utilized as light-emitting source due to the rapid advances in technology. In addition to lighting equipment, general traffic signs, billboards, lights, etc., are also replaced by the use of light-emitting diodes as a light source. As mentioned above, the use of light-emitting diodes as a light source has the advantages of power saving and greater brightness, and thus has become more and more common in use.
As shown in FIG. 1, it is a schematic diagram of an optical path of a lighting system using LED as a light source in the prior art. The lighting system includes an illuminated plane 1 and an LED light source 2 disposed on a side of the illuminated plane 1. The LED light source 2 includes a light-emitting surface 3, which emits numerous light rays 4 and illuminates the illuminated plane 1. It is conceivable that no matter where the LED light source 2 is placed on the illuminated plane 1, a part of the light rays 4 emitted by the light-emitting surface 3 will certainly be emitted toward the near side of the illuminated plane 1, while the other part will certainly emit toward the far side of the illuminated plane 1. It is because of the above unavoidable light irradiation structure that the light emitted toward the near side of the illuminated plane 1 will be attenuated relative to the light emitted toward the far side of the illuminated plane 1 regardless of whether the light is directed to the far side or the near side, light has the same initial luminance value, the brightness of the irradiated plane 1 differs from the distance of the LED light source 2, that is, the illumination intensity of the illuminated plane 1 is different.
This uneven lighting effect to some occasions, such as exhibition halls, showrooms, or some lighting in shopping malls, due to uneven lighting effects, that is, uneven illumination will be reduced to display items to visitors or purchase Visual effects, thereby reducing the visual impression of the quality of items displayed.